(19)
(11) EP 1 063 681 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
12.08.2009 Bulletin 2009/33

(43) Date of publication A2:
27.12.2000 Bulletin 2000/52

(21) Application number: 00113404.8

(22) Date of filing: 23.06.2000
(51) International Patent Classification (IPC): 
H01J 61/12(2006.01)
 H01J 61/82(2006.01)
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 25.06.1999 JP 18028599

(71) Applicant: Stanley Electric Co., Ltd.
Meguro-ku Tokyo 153-8636 (JP)

(72) Inventors:
  • Muto, Masaaki
    Yokohama-shi, Kanagawa, 225-0014 (JP)
  • Shibayama, Shigeru
    Yokohama-shi, Kanagawa, 225-0014 (JP)
  • Shimada, Hiroharu
    Tokyo, 153-8636 (JP)
  • Sato, Isamu
    Tokyo, 153-8636 (JP)
  • Omori, Shinya
    Yokohama-shi, Kanagawa, 225-0014 (JP)
  • Yaguchi, Yasuhisa
    Yokohama-shi, Kanagawa, 225-0014 (JP)
  • Matsubara, Naoyuki
    Yokohama-shi, Kanagawa, 225-0014 (JP)
  • Takao, Yoshifumi
    Yokohama-shi, Kanagawa, 225-0014 (JP)
  • Nagahara, Toshiyuki
    Yokohama-shi, Kanagawa, 225-0014 (JP)

(74) Representative: Geyer, Ulrich F. et al
WAGNER & GEYER, Patentanwälte, Gewürzmühlstrasse 5
80538 München
80538 München (DE)

   


(54) Metal halide discharge lamps


(57) In high pressure discharge lamps such as related metal halide lamps (10), in addition to emitting light, mercury is employed as a buffer gas to increase the temperature of the arc tube (1), to promote the evaporation of light-emitting material, and to regulate arc tube (1) pressure. However, mercury itself is damaging to the environment and it has therefore been the desire of manufacturers to develop an arc tube (1) that does not employ mercury. It is the object of the present invention to provide an arc tube (1) with improved chromaticity and start-up characteristics that does not contain mercury, and to provide a vehicle headlamp (11) equipped with a metal halide lamp (10) having this arc tube (1), where both the evaporation of low melting point metal halides is promoted and the start-up characteristics of the arc tube (1) are improved.







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